ALARA principles in practice: reduced frame and pulse rates for middle meningeal artery embolization.

Objective: As the prevalence of neuroendovascular interventions increases, it is critical to mitigate unnecessary radiation for patients, providers, and health care staff. Our group previously demonstrated reduced radiation dose and exposure during diagnostic angiography by reducing the default pulse and frame rates. We applied the same technique for basic neuroendovascular interventions. Methods: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. We studied consecutive, unilateral middle meningeal artery embolizations treated with particles. Total radiation dose, radiation per angiographic run, total radiation exposure, and exposure per run were calculated. Multivariable log-linear regression was performed to account for patient body mass index (BMI), number of angiographic runs, and number of vessels catheterized. Results: A total of 20 consecutive, unilateral middle meningeal artery embolizations were retrospectively analyzed. The radiation reduction protocol was associated with a 39.2% decrease in the total radiation dose and a 37.1% decrease in radiation dose per run. The protocol was associated with a 41.6% decrease in the total radiation exposure and a 39.5% decrease in exposure per run. Conclusions: Radiation reduction protocols can be readily applied to neuroendovascular interventions without increasing overall fluoroscopy time and reduce radiation dose and exposure by 39.2% and 41.6% respectively. We strongly encourage all interventionalists to be cognizant of pulse rate and frame rate when performing routine interventions.

Femoral versus radial access for middle meningeal artery embolization for chronic subdural hematomas: multicenter propensity score matched study.

BACKGROUND: With transradial access (TRA) being more progressively used in neuroendovascular procedures, we compared TRA with transfemoral access (TFA) in middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH). METHODS: Consecutive patients undergoing MMAE for cSDH at 14 North American centers (2018-23) were included. TRA and TFA groups were compared using propensity score matching (PSM) controlling for: age, sex, concurrent surgery, previous surgery, hematoma thickness and side, midline shift, and pretreatment antithrombotics. The primary outcome was access site and overall complications, and procedure duration; secondary endpoints were surgical rescue, radiographic improvement, and technical success and length of stay. RESULTS: 872 patients (median age 73 years, 72.9% men) underwent 1070 MMAE procedures (54% TFA vs 46% TRA). Access site hematoma occurred in three TFA cases (0.5%; none required operative intervention) versus 0% in TRA (P=0.23), and radial-to-femoral conversion occurred in 1% of TRA cases. TRA was more used in right sided cSDH (58.4% vs 44.8%; P<0.001). Particle embolics were significantly higher in TFA while Onyx was higher in TRA (P<0.001). Following PSM, 150 matched pairs were generated. Particles were more utilized in the TFA group (53% vs 29.7%) and Onyx was more utilized in the TRA group (56.1% vs 31.5%) (P=0.001). Procedural duration was longer in the TRA group (median 68.5 min (IQR 43.1-95) vs 59 (42-84); P=0.038), and radiographic success was higher in the TFA group (87.3% vs 77.4%; P=0.036). No differences were noted in surgical rescue (8.4% vs 10.1%, P=0.35) or technical failures (2.4% vs 2%; P=0.67) between TFA and TRA. Sensitivity analysis in the standalone MMAE retained all associations but differences in procedural duration. CONCLUSIONS: In this study, TRA offered comparable outcomes to TFA in MMAE for cSDH in terms of access related and overall complications, technical feasibility, and functional outcomes. Procedural duration was slightly longer in the TRA group, and radiographic success was higher in the TFA group, with no differences in surgical rescue rates.

Serial dilation to enable ulnar artery access for endovascular neurointervention: Technical report and systematic review of the literature.

BACKGROUND: For rare neuro-endovascular cases in which transfemoral access is not feasible and the palmar circulation is insufficient for radial artery access, ulnar artery access may be considered. MATERIALS AND METHODS: Mechanical thrombectomy via ulnar artery access was performed to preserve the dominant radial artery. The ulnar artery was serial dilated to 7-French with microdilator. Angiography was performed using a diagnostic catheter. The sheath was exchanged for a guide catheter, and a triaxial system was inserted. A mechanical thrombectomy was performed. The systematic literature review included all studies pertaining to techniques for ulnar artery access for neurointervention in the last 20 years (2003-2023) published in the PubMed, Web of Science, and Embase databases. RESULTS: 67-year-old male developed left MCA syndrome in the setting of an infected abdominal aortic endograft. A transfemoral approach was ruled out due to concern for crossing the infected endograft. Allen test and ultrasound demonstrated that the right radial artery was of adequate size for access, but the ulnar artery was insufficient to support the palmar arch. Mechanical thrombectomy resulted in TICI 3 reperfusion. Systematic review of the literature yielded 2 case series and 1 case report of transulnar neurovascular procedures. Access site complications were rare and included 3 access site hematomas and 1 ulnar artery occlusion. CONCLUSION: We report our technique of serial dilation of the ulnar artery for neuroendovascular procedures and provide a systematic review of the literature for complication avoidance in ulnar artery access.

Simultaneous resolution of arachnoid cyst and chronic subdural hematoma after middle meningeal artery embolization: illustrative case.

BACKGROUND: Arachnoid cysts are cerebrospinal fluid-filled spaces that are typically congenital and treated conservatively or with fenestration when symptomatic. Chronic subdural hematomas (cSDHs) can arise in the presence of arachnoid cysts due to fragile leptomeningeal vessels or veins within the cyst wall or cyst lumen, leading to bleeding and subsequent hematoma formation. Middle meningeal artery (MMA) embolization is regularly used for the treatment of cSDH as an alternative to craniotomy and evacuation. OBSERVATIONS: Here, the authors present the first known report of the simultaneous resolution of an arachnoid cyst and cSDH following MMA embolization in an adult. A 24-year-old male presented to the emergency department with 1 month of worsening headaches. Imaging revealed the presence of a cSDH and ipsilateral arachnoid cyst. The cSDH was treated with MMA embolization using coils exclusively. Follow-up imaging 4 months after embolization demonstrated simultaneous resolution of both the hematoma and the arachnoid cyst. LESSONS: MMA embolization has been used for the treatment of cSDH. In cases in which the hematoma is related to an arachnoid cyst, MMA embolization can also lead to the concurrent resolution of both pathologies. https://thejns.org/doi/10.3171/CASE24192.

Feasibility of Endovascular Deep Brain Stimulation of Anterior Nucleus of the Thalamus for Refractory Epilepsy.

BACKGROUND AND OBJECTIVES: Deep brain stimulation (DBS) has developed into an effective therapy for several disease states including treatment-resistant Parkinson disease and medically intractable essential tremor, as well as segmental, generalized and cervical dystonia, and obsessive-compulsive disorder (OCD). Dystonia and OCD are approved with Humanitarian Device Exemption. In addition, DBS is also approved for the treatment of epilepsy in the anterior nucleus of the thalamus. Although overall considered an effective treatment for Parkinson disease and epilepsy, a number of specific factors determine the treatment success for DBS including careful patient selection, effective postoperative programming of DBS devices and accurate electrode placement. Furthermore, invasiveness of the procedure is a rate limiter for patient adoption. It is desired to explore a less invasive way to deliver DBS therapy. METHODS: Here, we report for the first time the direct comparison of endovascular and parenchymal DBS in a triplicate ovine model using the anterior nucleus of the thalamus as the parenchymal target for refractory epilepsy. RESULTS: Triplicate ovine studies show comparable sensing resolution and stimulation performance of endovascular DBS with parenchymal DBS. CONCLUSION: The results from this feasibility study opens up a new frontier for minimally invasive DBS therapy.

The inactive X chromosome drives sex differences in microglial inflammatory activity in human glioblastoma.

Biological sex is an important risk factor in cancer, but the underlying cell types and mechanisms remain obscure. Since tumor development is regulated by the immune system, we hypothesize that sex-biased immune interactions underpin sex differences in cancer. The male-biased glioblastoma multiforme (GBM) is an aggressive and treatment-refractory tumor in urgent need of more innovative approaches, such as considering sex differences, to improve outcomes. GBM arises in the specialized brain immune environment dominated by microglia, so we explored sex differences in this immune cell type. We isolated adult human TAM-MGs (tumor-associated macrophages enriched for microglia) and control microglia and found sex-biased inflammatory signatures in GBM and lower-grade tumors associated with pro-tumorigenic activity in males and anti-tumorigenic activity in females. We demonstrated that genes expressed or modulated by the inactive X chromosome facilitate this bias. Together, our results implicate TAM-MGs, specifically their sex chromosomes, as drivers of male bias in GBM.

Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations.

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

Treatment of pediatric intracranial aneurysms: institutional case series and systematic literature review.

INTRODUCTION: Pediatric intracranial aneurysms (IAs) are rare and have distinct clinical profiles compared to adult IAs. They differ in location, size, morphology, presentation, and treatment strategies. We present our experience with pediatric IAs over an 18-year period using surgical and endovascular treatments and review the literature to identify commonalities in epidemiology, treatment, and outcomes. METHODS: We identified all patients < 20 years old who underwent treatment for IAs at our institution between 2005 and 2020. Medical records and imaging were examined for demographic, clinical, and operative data. A systematic review was performed to identify studies reporting primary outcomes of surgical and endovascular treatment of pediatric IAs. Demographic information, aneurysm characteristics, treatment strategies, and outcomes were collected. RESULTS: Thirty-three patients underwent treatment for 37 aneurysms over 18 years. The mean age was 11.4 years, ranging from one month to 19 years. There were 21 males (63.6%) and 12 females (36.4%), yielding a male: female ratio of 1.75:1. Twenty-six (70.3%) aneurysms arose from the anterior circulation and 11 (29.7%) arose from the posterior circulation. Aneurysmal rupture occurred in 19 (57.5%) patients, of which 8 (24.2%) were categorized as Hunt-Hess grades IV or V. Aneurysm recurrence or rerupture occurred in five (15.2%) patients, and 5 patients (15.2%) died due to sequelae of their aneurysms. Twenty-one patients (63.6%) had a good outcome (modified Rankin Scale score 0-2) on last follow up. The systematic literature review yielded 48 studies which included 1,482 total aneurysms (611 with endovascular treatment; 656 treated surgically; 215 treated conservatively). Mean aneurysm recurrence rates in the literature were 12.7% and 3.9% for endovascular and surgical treatment, respectively. CONCLUSIONS: Our study provides data on the natural history and longitudinal outcomes for children treated for IAs at a single institution, in addition to our treatment strategies for various aneurysmal morphologies. Despite the high proportion of patients presenting with rupture, good functional outcomes can be achieved for most patients.

Traumatic Brain Injuries After Falls From Height vs Falls at the US-Mexico Border Wall.

This cohort study examines the incidence, severity, and mortality of fall-related injuries among migrants at the US-Mexico border in San Diego, California.

ARISE I Consensus Statement on the Management of Chronic Subdural Hematoma.

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.

The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas.

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/µL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study.

BACKGROUND AND OBJECTIVES: The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE. METHODS: Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes. RESULTS: Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations. CONCLUSION: We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

Optimizing suction force in mechanical thrombectomy: Priming the aspiration tubing with air versus saline.

Objective: We sought to investigate how priming the tube between air versus air mixed with saline ex vivo influenced suction force. We examined how priming the tube influenced peak suction force and time to achieve peak suction force between both modalities. Methods: Using a Dwyer Instruments (Dwyer Instruments Inc., Michigan City, IN, USA), INC Digitial Pressure Gauge, we were able to connect a .072 inch aspiration catheter to a rotating hemostatic valve and to aspiration tubing. We recorded suction force measured in negative inches of Mercury (inHg) over 10 iterations between having the aspiration tube primed with air alone versus air mixed with saline. A test was used to compare results between both modalities. Results: Priming the tube with air alone compared to air mixed with saline was found to have an increased average max suction force (-28.60 versus -28.20 in HG, p<0.01). We also identified a logarithmic curve of suction force across time in which time to maximal suction force was more prompt with air compared with air mixed with saline (13.8 seconds versus 21.60 seconds, p<0.01). Conclusions: Priming the tube with air compared to air mixed with saline suggests that not only is increased maximal suction force achieved, but also the time required to achieve maximal suction force is less. This data suggests against priming the aspiration tubing with saline and suggests that the first pass aspiration primed with air may have the greatest suction force.

Reducing frame rate and pulse rate for routine diagnostic cerebral angiography: ALARA principles in practice.

OBJECTIVE: Diagnostic cerebral angiograms (DCAs) are widely used in neurosurgery due to their high sensitivity and specificity to diagnose and characterize pathology using ionizing radiation. Eliminating unnecessary radiation is critical to reduce risk to patients, providers, and health care staff. We investigated if reducing pulse and frame rates during routine DCAs would decrease radiation burden without compromising image quality. METHODS: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. Radiation doses and exposures were calculated. Two endovascular neurosurgeons reviewed randomly selected angiograms of both doses and blindly assessed their quality. RESULTS: A total of 40 consecutive angiograms were retrospectively analyzed, 20 prior to the protocol change and 20 after. After the intervention, radiation dose, radiation per run, total exposure, and exposure per run were all significantly decreased even after adjustment for BMI (all p<0.05). On multivariable analysis, we identified a 46% decrease in total radiation dose and 39% decrease in exposure without compromising image quality or procedure time. CONCLUSIONS: We demonstrated that for routine DCAs, pulse rate of 7.5 with a frame rate of 4.0 is sufficient to obtain diagnostic information without compromising image quality or elongating procedure time. In the interest of patient, provider, and health care staff safety, we strongly encourage all interventionalists to be cognizant of radiation usage to avoid unnecessary radiation exposure and consequential health risks.

Standalone middle meningeal artery embolization versus middle meningeal artery embolization with concurrent surgical evacuation for chronic subdural hematomas: a multicenter propensity score matched analysis of clinical and radiographic outcomes.

BACKGROUND: Middle meningeal artery embolization (MMAE) has emerged as a promising therapy for chronic subdural hematomas (cSDHs). The efficacy of standalone MMAE compared with MMAE with concurrent surgery is largely unknown. METHODS: cSDH patients who underwent successful MMAE from 14 high volume centers with at least 30 days of follow-up were included. Clinical and radiographic variables were recorded and used to perform propensity score matching (PSM) of patients treated with standalone MMAE or MMAE with concurrent surgery. Multivariable logistic regression models were used for additional covariate adjustments. The primary outcome was recurrence requiring surgical rescue, and the secondary outcome was radiographic failure defined as <50% reduction of cSDH thickness. RESULTS: 722 MMAE procedures in 588 cSDH patients were identified. After PSM, 230 MMAE procedures remained (115 in each group). Median age was 73 years, 22.6% of patients were receiving anticoagulation medication, and 47.9% had no preoperative functional disability. Median midline shift was 4 mm and cSDH thickness was 16 mm, representing modestly sized cSDHs. Standalone MMAE and MMAE with surgery resulted in similar rates of surgical rescue (7.8% vs 13.0%, respectively, P=0.28; adjusted OR (aOR 0.73 (95% CI 0.20 to 2.40), P=0.60) and radiographic failure (15.5% vs 13.7%, respectively, P=0.84; aOR 1.08 (95% CI 0.37 to 2.19), P=0.88) with a median follow-up duration of 105 days. These results were similar across subgroup analyses and follow-up durations. CONCLUSIONS: Standalone MMAE led to similar and durable clinical and radiographic outcomes as MMAE combined with surgery in select patients with moderately sized cSDHs and mild clinical disease.

How do children fare compared with adults? Comparing relative outcomes after thrombectomy for acute ischemic stroke due to large-vessel occlusion.

OBJECTIVE: Safety and efficacy data for endovascular thrombectomy for acute ischemic stroke secondary to large-vessel occlusion in children are lacking compared with those for adults. We undertook an updated systematic review and meta-analysis of endovascular thrombectomy in children and compared their outcomes with adult data. METHODS: We searched PubMed, Medline, and EMBASE databases to identify prospective and retrospective studies describing patients <18 years treated with endovascular thrombectomy for acute ischemic stroke due to large-vessel occlusion. RESULTS: Eight pediatric studies were included (n = 192). Most patients were male (53.1 %), experienced anterior circulation large-vessel occlusion (81.8 %), and underwent endovascular thrombectomy by stent retreiver (70.7 %). The primary outcome was change in National Institutes of Health Stroke Scale score from presentation to 24 h after thrombectomy. Secondary outcomes included modified Rankin scale score improvement and 90-day score, recanalization rates, procedural complications, and mortality rates. After treatment, 88.5% of children had successful recanalization; the mean National Institutes of Health Stroke Scale score reduction was 7.37 (95 % CI 5.11-9.63, p < 0.01). The mean reduction of 6.87 (95 %CI 5.00-8.73, p < 0.01) for adults in 5 clinical trials (n = 634) was similar (Qb = 0.11; p = 0.74). Children experienced higher rates of good neurological outcome (76.1 % vs. 46.0 %, p < 0.01) and revascularization (88.5 % vs. 72.3 %, p < 0.01), fewer major periprocedural complications (3.6 % vs. 30.4 %, p < 0.01), and lower mortality (1.0 % vs. 12.9 %, p < 0.01). CONCLUSIONS: Endovascular thrombectomy may be safe and effective treatment for acute ischemic stroke due to large-vessel occlusion in children. The aggregated data demonstrated high rates of revascularization, favorable long-term neurological outcomes, and low complication rates.

Safety of middle meningeal artery embolization for treatment of subdural hematoma: A nationwide propensity score matched analysis.

OBJECTIVE: Middle meningeal artery embolization (MMAe) has burgeoned as a treatment for chronic subdural hematoma (cSDH). This study evaluates the safety and short-term outcomes of MMAe patients relative to traditional treatment approaches. METHODS: In this retrospective large database study, adult patients in the National Inpatient Sample from 2012-2019 with a diagnosis of cSDH were identified. Cost of admission, length of stay (LOS), discharge disposition, and complications were analyzed. Propensity score matching (PSM) was utilized. RESULTS: A total of 123,350 patients with cSDH were identified: 63,450 without intervention, 59,435 surgery only, 295 MMAe only, and 170 surgery plus MMAe. On PSM analysis, MMAe did not increase the risk of inpatient complications or prolong the length of stay compared to conservative management (p>0.05); MMAe had higher cost ($31,170 vs. $10,768, p<0.001) than conservative management, and a lower rate of nonroutine discharge (53.8% vs. 64.3%, p=0.024). Compared to surgery, MMAe had shorter LOS (5 vs. 7 days, p<0.001), and lower rates of neurological complications (2.7% vs. 7.1%, p=0.029) and nonroutine discharge (53.8% vs. 71.7%, p<0.001). There was no significant difference in cost (p>0.05). CONCLUSIONS: MMAe had similar LOS and decreased odds of adverse discharge with a modest cost increase compared to conservative management. There was no difference in inpatient complications. Compared to surgery, MMAe treatment was associated with decreased LOS and rates of neurological complications and nonroutine discharge. This nationwide analysis supports the safety of MMAe to treat cSDH.

Direct Transorbital Approach for Treatment of Carotid Cavernous Fistula: An Illustrative Case Series.

BACKGROUND AND OBJECTIVES: Endovascular techniques have become the first-line treatment for carotid-cavernous fistulas (CCFs). Direct transorbital venous access may be used if anatomic constraints limit standard transarterial or transvenous access. We describe our institutional experience with the transorbital approach for Barrow Type A-D CCFs. METHODS: Patients with CCFs undergoing transorbital endovascular treatment at our institution between 2017 and 2019 were retrospectively reviewed. Demographic, treatment, and outcome data were collected. RESULTS: Eight patients met inclusion criteria, 4 female and 4 male patients. The mean age was 43 years, with 6 right-sided CCF and 2 left-sided CCFs. Symptoms were present for an average of 1.5 months before treatment. All patients presented with eye pain and subjective visual changes. Seven (87.5%) patients presented with proptosis, 6 (75%) patients had elevated intraocular pressure (IOP), and 3 (37.5%) patients had ophthalmoplegia. Six CCFs (75%) were spontaneous, and 2 CCFs (25%) were traumatic. Barrow types were A (n = 1), B (n = 1), C (n = 1), and D (n = 5). All patients underwent direct percutaneous transorbital embolization with coils followed by Onyx. Three patients had undergone prior transarterial and/or transvenous treatment. A radiographic cure was obtained in all patients after direct transorbital embolization. After CCF cure, cranial nerve palsies resolved in 66.7% of patients, visual acuity in the affected eye was improved or stable in 75% of patients, and IOP had normalized in 85.7% of patients. Proptosis improved in all patients, with complete resolution in 75%. CONCLUSION: Direct transorbital embolization is a safe and potentially curative treatment for all 4 Barrow types of CCFs.

Histology of the Porous Oculomotorius: Relevance to Anterior Skull Base Approaches.

Objective Mobilization of cranial nerve III (CNIII) at its dural entry site is commonly described to avoid damage from stretching during approaches to the parasellar, infrachiasmatic, posterior clinoid, and cavernous sinus regions. The histologic relationships of CNIII as it traverses the dura, and the associated surgical implications are nonetheless poorly described. We herein assess the histology of the CNIII-dura interface as it relates to surgical mobilization of the nerve. Methods A fronto-orbitozygomatic temporopolar approach was performed on six adult cadaveric specimens. The CNIII-dural entry site was resected and histologically processed. The nerve-tissue planes were assessed by a neuropathologist. Results Histologic analysis demonstrated that CNIII remained separate from the dura within the oculomotor cistern (porous oculomotorius up to the oculomotor foramen). Fusion of the epineurium of CNIII and the connective tissue of the dura was seen at the level of the foramen, with no clear histologic plane identified between these structures. Conclusion CNIII may be directly mobilized within the oculomotor cistern, while dissections of CNIII distal to the oculomotor foramen should maintain a thin layer of connective tissue on the nerve.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Predictors of Clinical and Radiographic Failure from 636 Embolizations.

Background Knowledge regarding predictors of clinical and radiographic failures of middle meningeal artery (MMA) embolization (MMAE) treatment for chronic subdural hematoma (CSDH) is limited. Purpose To identify predictors of MMAE treatment failure for CSDH. Materials and Methods In this retrospective study, consecutive patients who underwent MMAE for CSDH from February 2018 to April 2022 at 13 U.S. centers were included. Clinical failure was defined as hematoma reaccumulation and/or neurologic deterioration requiring rescue surgery. Radiographic failure was defined as a maximal hematoma thickness reduction less than 50% at last imaging (minimum 2 weeks of head CT follow-up). Multivariable logistic regression models were constructed to identify independent failure predictors, controlling for age, sex, concurrent surgical evacuation, midline shift, hematoma thickness, and pretreatment baseline antiplatelet and anticoagulation therapy. Results Overall, 530 patients (mean age, 71.9 years ± 12.8 [SD]; 386 men; 106 with bilateral lesions) underwent 636 MMAE procedures. At presentation, the median CSDH thickness was 15 mm and 31.3% (166 of 530) and 21.7% (115 of 530) of patients were receiving antiplatelet and anticoagulation medications, respectively. Clinical failure occurred in 36 of 530 patients (6.8%, over a median follow-up of 4.1 months) and radiographic failure occurred in 26.3% (137 of 522) of procedures. At multivariable analysis, independent predictors of clinical failure were pretreatment anticoagulation therapy (odds ratio [OR], 3.23; P = .007) and an MMA diameter less than 1.5 mm (OR, 2.52; P = .027), while liquid embolic agents were associated with nonfailure (OR, 0.32; P = .011). For radiographic failure, female sex (OR, 0.36; P = .001), concurrent surgical evacuation (OR, 0.43; P = .009), and a longer imaging follow-up time were associated with nonfailure. Conversely, MMA diameter less than 1.5 mm (OR, 1.7; P = .044), midline shift (OR, 1.1; P = .02), and superselective MMA catheterization (without targeting the main MMA trunk) (OR, 2; P = .029) were associated with radiographic failure. Sensitivity analyses retained these associations. Conclusion Multiple independent predictors of failure of MMAE treatment for chronic subdural hematomas were identified, with small diameter (<1.5 mm) being the only factor independently associated with both clinical and radiographic failures. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Chaudhary and Gemmete in this issue.